Estimate of the Cosmological Bispectrum from the MAXIMA-1 Cosmic Microwave Background Map

We use the measurement of the cosmic microwave background taken during the MAXIMA-1 flight to estimate the bispectrum of cosmological perturbations. We propose an estimator for the bispectrum that is appropriate in the flat sky approximation, apply it to the MAXIMA-1 data, and evaluate errors using bootstrap methods. We compare the estimated value with what would be expected if the sky signal were Gaussian and find that it is indeed consistent, with a ${\ensuremath{\chi}}^{2}$ per degree of freedom of approximately unity. This measurement places constraints on models of inflation.